Dear Clare,
I just saw your monarch sighting appear on the migration map. How fascinating--and
unusual!

Of course
nobody can answer your question about where the monarch originated definitively.
It is certainly possible to see a monarch this early in MA. I know we
have had early records before. In fact, a 12-year old girl saw a monarch
on Cape Cod on April 7, 1997 and even sent a picture of its wings. >>

Cold temperatures
are the obvious reason you wouldn't expect a monarch so early.
An additional reason, however, is that the monarch population is so small
in April. Adult monarch butterflies are relatively rare right now. This
is because the overwintering generation from Mexico has died and we are
waiting for their offspring to develop.

One possible
explanation for your sighting is that your monarch did not come from Mexico.
Some monarchs do overwinter along the Atlantic Coast as long as frost
does not kill them. During the winter of 2005/2006, two tagged
butterflies stayed in Virginia all winter, providing direct evidence
of this. Thus, it's possible that the monarch you saw came from the East
Coast. (You may recall the HUGE migration last fall. Perhaps numbers along
the coast were higher this winter.) Our migration
map shows where the monarchs overwintered this year. Watch the animated
map; it seems to show monarchs moving inland from the Carolina coasts.

The fact
that you are on the ocean is of interest. Monarchs avoid crossing open
water, so coastlines funnel the butterflies as they travel. Thus, even
though there are very few monarchs now, those that are in your region
might be blown to the coast and then travel along its edge.

Another possibility
is that the monarch was released as part of a wedding or other celebration
(or even released from a lab). Many companies now sell captive-raised
monarchs for such celebrations, although it would be early to do so in
April.

Finally,
the fact that people are watching and reporting their observations means
the "unusual" goes on record. Perhaps it's more common than
we realize for a small number of monarchs to be seen each spring in MA,
but they previously went unrecorded.

These are
a few of my thoughts. Thank you so much for reporting what you saw. It's
exciting to hear from you!

Regards,
Elizabeth Howard
Journey North

Here
is the letter I wrote to Clare Walker Leslie in response to her question.
I hope the ideas in my letter will help you review the letters students
in your class write.